Plasminogen-fibrin complex (PLG/FBN)

Plasminogen is a circulating zymogen that is converted into the active serine protease plasmin, which is the primary enzyme responsible for the degradation of fibrin clots (fibrinolysis) [1.1.1, 1.2.1]. Fibrin serves as both the structural scaffold of blood clots and a critical cofactor that significantly enhances the activation of plasminogen by tissue-type plasminogen activator (tPA) [1.1.1, 1.3.2]. This localized activation ensures that clot dissolution occurs specifically at the site of thrombus formation without causing systemic proteolysis [1.1.3, 1.2.2]. The plasminogen-fibrin system is a major therapeutic target in cardiovascular medicine [1.2.1, 1.2.4]. Thrombolytic agents like alteplase are used to dissolve occlusive clots in myocardial infarction and ischemic stroke by promoting plasmin generation [1.1.3, 1.3.2]. Conversely, antifibrinolytic drugs like tranexamic acid inhibit this interaction to manage heavy bleeding in trauma or surgery [1.2.1, 1.3.2]. Beyond its role in hemostasis, the system is involved in tissue remodeling, wound healing, and the inflammatory response [1.2.1, 1.2.2]. Dysregulation of this system can lead to either pathological thrombosis or life-threatening hemorrhage [1.1.5, 1.4.1].

Other names

Plasminogen/fibrinPlasminogen-fibrin interactionFibrinolytic systemPlasminogen-fibrin system

Thrombolytic agents (e.g., alteplase) bind to fibrin and activate fibrin-bound plasminogen into plasmin, which then proteolytically degrades the fibrin meshwork [1.3.2]. Antifibrinolytic agents (e.g., tranexamic acid) competitively bind to the lysine-binding sites on plasminogen, preventing its association with fibrin and subsequent activation, thereby stabilizing the clot [1.3.2].